If Sempron is 256kb and 333fsb and 1.67 to 2.0 Ghz for 2400+ to 2800+ it will, to not mince any words here, get absolutely slaughtered by Celeron D in the marketplace even if it is technically comparable. Sempron can afford to be one speed grade more ambitious than XP but that's it imo, so XP 2700+ = Sempron 2800+. Any less and the overall performance advantage will not be sufficient to overcome the Intel brandname, imo.